Physics : 20 Numbers of Multiple Choices Grade 9

Hi,

I have another 20 questions for you to practice.

As usual, if you have any question about this worksheet, please write it in the comment section below.

I will answer it in a simplest way that I can.

Warm regards,

Dee

1.  Calculate the pressure exerted by a woman dancer weighing 600 N standing 

     on a single heel of area 1 cm².

          a. 600 000 Pa 

          b. 600 Pa 

          c.     6 Pa    

          d. 6 000 000 Pa      

2.  The following statements are true for an object in equilibrium, except _______

          a. There is no resultant force.

          b. The forces on it must be balanced.

          c. The resultant force is equal to the weight of the object.

          d. The turning effects of the forces on it must be balanced.

3.  If a 35 N force is placed 2.0 m away from the pivot, the moment of the force 

     will be ________

          a.   0    Nm

          b. 17.5 Nm

          c. 35    Nm

          d. 70    Nm

4.  The moment of a force causes an object to ________

          a.  turn

          b.  accelerate

          c.  stop moving

          d.  slow down

5.  The instrument used to measure atmospheric pressure is called a/an ________

          a. ammeter

          b. barometer

          c. manometer

          d. potentiometer

6.  Calculate the pressure on the bottom of a swimming pool 2.5 m deep, 

     given that the density of water is 1000 kg/m³.

          a.       250 Pa

          b.     2500 Pa

          c.   25 000 Pa

          d. 250 000 Pa

7.  The figure below shows a boy standing at one end of a plank that is 1.5 m long.

     If the boy weighs 600 N, the moment due to his weight about the clamped 

     end is ________

          a.  900 Nm

          b.  400 Nm

          c.    90 Nm

          d.    40 Nm

8.  A non-uniform rod is balanced as shown in the diagram below.

     Given that the center of mass of the rod is 14.0 cm from the end marked A, 

     what is the mass of the rod?

          a.    40 g

          b.  100 g

          c. 1000 g

          d. 1140 g

9.  The diagram below shows a uniform meter rule balanced at its center of mass.

     A load of 8.0 N is hung at the 20 cm mark. At which position must a load of 5.0 N

     be hung in order to maintain equilibrium?

          a.  98 cm

          b.  75 cm

          c.  68 cm

          d.  52 cm

10. The following are ways in which energy can be transferred, except ________

          a.  by pushing.

          b.  by heating.

          c.  by electricity.

          d.  by placing the two objects next to each other.

11. The following are stores of chemical energy, except ________

          a. bread.

          b. books.

          c. petrol.

          d. batteries.

12. The device that transforms electrical energy to sound energy, and can also 

      produce heat energy, could be a/an ________

          a. music player

          b. stove

          c. fan

          d. iron

13. Which of the following diagrams shows a sphere in stable equilibrium?

14. A diver on a spring board undergoes the following energy conversion.

          a. Chemical -->    Electrical   --> Heat

          b. Chemical -->    Electrical   --> Kinetic

          c. Chemical -->      Elastic      --> Kinetic

          d. Chemical --> Gravitational --> Sound

15. When a lamp is supplied with 100 J of electrical energy, it produces 85 J of 

      heat energy. The rest is given out as light energy. What is the efficiency of 

      the lamp?

          a.   15%

          b. 100%

          c.    0 %

          d.   85%

16. A waterfall has ________

          a. strain energy

          b. gravitational potential energy

          c. nuclear energy

          d. electrical energy

17. An athlete of mass 50 kg runs up a hill. The foot of the hill is 400 m above 
      sea level. The summit is 1200 m above sea level. By how much does the 
      athlete's GPE increase?
          a.     50 J
          b.  200 000 J
          c.  400 000 J
          d.  600 000 J

18. A van of mass 2000 kg is travelling at 10 m/s. If the speed increases to 20 m/s, 
     by how much does its KE increase?
          a. 400 000 J
          b. 300 000 J
          c. 200 000 J
          d. 100 000 J

19. A package of 5 kg is lifted vertically through a distance of 10 m at 
      a constant speed. Taking the acceleration due to gravity to be 10 m/s², 
      what is the GPE gained by the package?
          a.  100 J
          b.     5 J
          c.  500 J
          d,  100 J

20. A bullet of mass 0.02 kg travels at a speed of 1200 m/s. 
      Calculate its kinetic energy.
          a.   1 440 J
          b.       24 J
          c.      144 J
          d. 14 400 J